Accuracy of Immunodiagnostic Tests for Active Tuberculosis Using Single and Combined Results: A Multicenter TBNET-Study

The clinical application of IFN-gamma release assays (IGRAs) has recently improved the diagnosis of latent tuberculosis infection. In a multicenter study of the Tuberculosis Network European Trialsgroup (TBNET) we aimed to ascertain in routine clinical practice the accuracy of a novel assay using selected peptides encoded in the mycobacterial genomic region of difference (RD) 1 for the diagnosis of active tuberculosis in comparison with tuberculin skin test (TST), QuantiFERON-TB GOLD In-Tube (Cellestis Ltd., Carnegie, Australia) and T-SPOT.TB (Oxfordimmunotec, Abingdon, UK)

Regulation of alternative splicing of CD45 by antagonistic effects of SR protein splicing factors.

CD45 is a transmembrane glycoprotein possessing tyrosine phosphatase activity, which is involved in cell signaling. CD45 is expressed on the surface of most leukocytes and can be alternatively spliced by the inclusion or skipping of three variable exons (4, 5, and 6 or A, B, and C) to produce up to eight isoforms. In T cells, the splicing pattern of CD45 isoforms changes after activation; naive cells express high m.w. isoforms of CD45 which predominantly express exon A (CD45RA), whereas activated cells lose expression of exon A to form low m.w. isoforms of CD45 including CD45RO. Little is known about the specific factors controlling the switch in CD45 splicing which occurs on activation. In this study, we examined the influence of the SR family of splicing factors, which, like CD45, are expressed in tissue-specific patterns and have been shown to modulate the alternative splicing of a variety of transcripts. We show that specific SR proteins have antagonistic effects on CD45 splicing, leading either to exon inclusion or skipping. Furthermore, we were able to demonstrate specific changes in the SR protein expression pattern during T cell activation

Dermatan sulfate domains defined by the novel antibody GD3A12, in normal tissues and ovarian adenocarcinomas.

Contains fulltext : 80140.pdf (publisher's version ) (Closed access)Dermatan sulfate (DS) expression in normal tissue and ovarian cancer was investigated using the novel, phage display-derived antibody GD3A12 that was selected against embryonic glycosaminoglycans (GAGs). Antibody GD3A12 was especially reactive with DS rich in IdoA-GalNAc4S disaccharide units. IdoA residues are important for antibody recognition as DS polymers with low numbers of IdoA residues were less reactive, and expression of the DS epimerase in ovarian carcinoma cells was associated with expression of the GD3A12 epitope. Moreover, staining of antibody GD3A12 was abolished by chondroitinase-B lyase digestion. Expression of DS domains defined by antibody GD3A12 was confined to connective tissue of most organs examined and presented as a typical fibrillar-type of staining. Differential expression of the DS epitopes recognized by antibodies GD3A12 and LKN1 (4/2,4 di-O-sulfated DS) was best seen in thymus and spleen, indicating differential expression of various DS domains in these organs. In ovarian carcinomas strong DS expression was found in the stromal parts, and occasionally on tumor cells. Partial co-localization in ovarian carcinomas was observed with decorin, versican and type I collagen suggesting a uniform distribution of this specific DS epitope. This unique anti-DS antibody may be instrumental to investigate the function, expression, and localization of specific DS domains in health and disease

Auxiliary splice factor U2AF26 and transcription factor Gfi1 cooperate directly in regulating CD45 alternative splicing.

Contains fulltext : 50839.pdf (publisher's version ) (Closed access)By alternative splicing, different isoforms of the transmembrane tyrosine phosphatase CD45 are generated that either enhance or limit T cell receptor signaling. We report here that CD45 alternative splicing is regulated by cooperative action of the splice factor U2AF26 and the transcription factor Gfi1. U2AF26 promoted formation of the less-active CD45RO by facilitating exon exclusion. Gfi1 antagonized that process by directly interacting with U2AF26, identifying a previously unknown link between a transcription factor and alternative splicing. The presence of Gfi1 led to formation of the more-active CD45RB, whereas loss of Gfi1 favored CD45RO production. We propose that the relative abundance of U2AF26 and Gfi1 determines the ratio of CD45 isoforms, thereby regulating T cell activation

Differential distribution of heparan sulfate glycoforms and elevated expression of heparan sulfate biosynthetic enzyme genes in the brain of mucopolysaccharidosis IIIB mice

Item does not contain fulltextThe primary pathology in mucopolysaccharidosis (MPS) IIIB is lysosomal storage of heparan sulfate (HS) glycosaminoglycans, leading to complex neuropathology and dysfunction, for which the detailed mechanisms remain unclear. Using antibodies that recognize specific HS glycoforms, we demonstrate differential cell-specific and domain-specific lysosomal HS-GAG distribution in MPS IIIB mouse brain. We also describe a novel neuron-specific brain HS epitope with broad, non-specific increase in the expression in all neurons in MPS IIIB mouse brain, including cerebellar granule neurons, which do not exhibit lysosomal storage pathology. This suggests that biosynthesis of certain HS glycoforms is enhanced throughout the CNS of MPS IIIB mice. Such a conclusion is further supported by demonstration of increased expression of multiple genes encoding enzymes essential in HS biosynthesis, including HS sulfotransferases and epimerases, as well as FGFs, for which HS serves as a co-receptor, in MPS IIIB brain. These data suggest that lysosomal storage of HS may lead to the increase in HS biosyntheses, which may contribute to the neuropathology of MPS IIIB by exacerbating the lysosomal HS storage

Sulfation of heparan sulfate associated with amyloid-beta plaques in patients with Alzheimer's disease.

Contains fulltext : 89112.pdf (publisher's version ) (Closed access)Alzheimer's disease (AD) is characterized by pathological lesions such as amyloid-beta (Abeta) plaques and cerebral amyloid angiopathy. Both these lesions consist mainly of aggregated Abeta protein and this aggregation is affected by macromolecules such as heparan sulfate (HS) proteoglycans. Previous studies demonstrated that HS enhances fibrillogenesis of Abeta and that this enhancement is dependent on the degree of sulfation of HS. In addition, it has been reported that these sulfation epitopes do not occur randomly but have a defined tissue distribution. Until now, the distribution of sulfation epitopes of HS has not yet been studied in human brain. We investigated whether a specific HS epitope is associated with Abeta plaques by performing immunohistochemistry on occipital neocortical and hippocampal tissue sections from AD patients using five HS epitope-specific phage display antibodies. Antibodies recognizing highly N-sulfated HS demonstrated the highest level of staining in both fibrillar Abeta plaques and non-fibrillar Abeta plaques, whereas antibodies recognizing HS regions with a lower degree of N-sulfate modifications were only immunoreactive with fibrillar Abeta plaques. Thus, our results suggest that a larger variety of HS epitopes is associated with fibrillar Abeta plaques, but the HS epitopes associated with non-fibrillar Abeta plaques seem to be more restricted, selectively consisting of highly N-sulfated epitopes.1 februari 201